Superconductivity at T$_{C }$=38 K in Pristine and Sulfur Doped Amorphous Carbon

Detailed dc magnetic studies perormed on pristine amorphous carbon and on sulfur doped amorphous carbon, clearly indicate the existence of inhomogeneous superconductivity with T$_{C }$ranging from 32 to 38 K. The superconducting phase fraction is about 0.5{\%}. Superconductivity is manifested by: (i) the diamagnetic shielding state, (ii) the Meissner effects and (iii) the typical M(H) hysteresis loops. The results indicate that amorphous carbon is a system with non-perculative superconducting phase. Chemical analysis shows that the amorphous carbon contains a small amount of sulfur. It is propossed that superconductivity stems from an unknown C-S phase immersed in amorphous carbon, thus it is concluded that s\'{u}lfur is a effective dopant to induce superconductivity in carbon (graphite) based materials. The various options for the C-S superconducting phase will be discussed.